Geography professor Monica Stephens has spent a lot of time putting haters on the map. Over at Humboldt State University in California where she is a professor, Stephens and a team of undergraduate students spent a year sorting through racial slurs on Twitter by location. And then she mapped them.

That meant searching for words like "nigger" and "fag" and "honkey." Stephens had a team of undergraduate students who sifted through 150,000 negative tweets.

Then Stephens' students went through about 90,000 tweets that used the N word to determine if they were actually negative, she told Tell Me More host Michel Martin. And it turns out, people who tweeted the N word were concentrated in certain areas.

"It tends to be in smaller towns, particularly in the Midwest, the Rust Belt area, more so than the South. But it was also quite present in Georgia and Alabama as well," Stephens said.

"Perhaps the most interesting concentration comes for references to 'wetback,' a slur meant to degrade Latino immigrants to the U.S. by tying them to 'illegal' immigration. Ultimately, this term is used most in different areas of Texas, showing the state's centrality to debates about immigration in the U.S. But the areas with significant concentrations aren't necessarily that close to the border, and neither do other border states who feature prominently in debates about immigration contain significant concentrations."

Stephens said that she and her researchers are still examining conclusions from their findings, but are interested in looking at tweets from small towns.

"Perhaps these are places that have experienced large amounts of job loss over recent years," Stephens told Martin.

But the map wasn't without criticism. In an FAQ aimed at negative feedback her research received, Stephens argues, among other things, that the spatial distributions on the map don't just reflect population density.

Take California, for instance. "The fact that there is so little activity on the map in California — home to an eighth of the entire U.S. population ... — should be a clue that something else besides population is at work in explaining these distributions," she wrote.

And Stephens said she also received criticism from white men who felt they were being discriminated against by not being included in the map. But Stephens did try to include white men.

"We also looked at words like honky, cracker and gringo. But actually those weren't necessarily used in a negative way very often," Stephens said on Tell Me More. "Particularly the word 'honky,' which often is referring to honky-tonk music and honky-tonk bars and people were using it in a very, very positive context."

The term "redneck," seemed like it could be another potential offender.

"A lot of [references] weren't really negative toward rednecks," Stephens said. "And they were also generally leveraged by people of the same group."

And it turns out, many of the slurs were used by members of the group in question.